Generally a coastal species, the white-bellied sea eagle can also be found further inland along rivers and lakes.

The impressive white-bellied sea eagle is known to soar to great heights, gliding with its wings held in a stiff ‘V’ shape.

The white-bellied sea eagle generally feeds on aquatic species, from fish and sea snakes to turtles and water birds, but may occasionally take terrestrial species, including livestock.

An efficient predator, the white-bellied sea eagle often catches its prey by performing spectacular swoops.

The white-bellied sea eagle is classified as Least Concern (LC) on the IUCN Red List (1), and is listed on Appendix II of CITES (6).

A relatively large and slender eagle (2) (4) (5) (7), the white-bellied sea eagle (Haliaeetus leucogaster) is a grey and white bird of prey (4) (5) with long, broad wings and a short, wedge- or diamond-shaped tail (2) (3) (4). The head, neck and underparts of this impressive species are white, whereas the back and upper surface of the black-tipped wings are grey (2) (3) (4) (5) (8). The white-bellied sea eagle’s tail has a grey or blackish base (3) (4) (8) (9) and a white tip (4).

The white-bellied sea eagle’s large, hooked beak (8) (10) is bluish-grey, grey or dark grey (4) (8) (9) and has a blackish tip (4). The patch of skin at the base of the beak, which is known as the cere, is light bluish-grey to dark grey (5) (9), and the eyes are brown (5) (8). White or cream-coloured legs and feet (2) (5), which are distinctly unfeathered on the lower portion (5) (9), give way to black talons (8).

Male and female white-bellied sea eagles are similar in appearance, although females tend to be larger than males (4). However, juveniles of this species look quite different from the adults, with their colouration gradually changing over the first few years as they complete several moults, becoming increasingly paler until they attain the adult colouration (2) (3) (4) (5). Young white-bellied sea eagles are dark brown on the upperparts, which are patterned with creamy markings (3) (4). The head, neck and underparts have a creamy or buffish colouration (3) (4), and the underwings have a large, pale patch or panel across the base of the primary feathers (3) (5). Unlike that of the adult, the juvenile white-bellied sea eagle’s tail is whitish with a broad brownish band on the tip (2) (3) (5). The cere, legs and feet are similar in colour to those of the adult bird (2) (5).

Sometimes soaring to great heights (9), the white-bellied sea eagle is known to glide with its wings held in a stiff ‘V’ shape (2) (3) (9) (10) (11). This species flies with strong wingbeats (9) described as being like a powerful rowing action (5). At rest, the white-bellied fish eagle perches upright on bare branches close to water (9).

The white-bellied sea eagle has a very distinctive call, which has been described as being a loud, goose-like honk or cackle (3) (5) (7) (10) (12). This species is particularly noisy around the nesting site during the breeding season (7) (9), and juvenile white-bellied sea eagles begging for food add to the noise by giving a prolonged yelping or wailing cry (5).

The white-bellied sea eagle occurs in South and Southeast Asia, New Guinea and Australia (4) (11) (13) (14). Its distribution stretches from India and Sri Lanka east to southern China and then southwards through Thailand, Vietnam, the Malay Archipelago and the Philippines to Australia (4) (9) (13) (15). This species has also been recorded as a vagrant on Christmas Island and in Taiwan (13).

In Australia, the white-bellied sea eagle can be found along the coastline of mainland Australia, as well as in Tasmania and on some offshore islands (4) (15), including Barrow Island (8). In certain parts of Australia, particularly in the east, this species is also known to be found inland along some of the larger waterways (4).

Breeding in the white-bellied sea eagle is known to only occur in a relatively small area of its range, in a patchy distribution along the coastline from Queensland to Victoria and to Tasmania. Some breeding has also been noted at sites further inland, such as around the Murray River (4).

The white-bellied sea eagle is generally found in coastal habitats (2) (3) (4) (5) (9) (15), including offshore islands (4) (8). However, it is also known to occur further inland along rivers, lakes, reservoirs and estuaries (2) (10) (11) (15), as well as on lagoons (4) (9). Although the white-bellied sea eagle is usually seen in coastal lowlands (4), it has been recorded at elevations of up to 1,400 metres in some areas of its range (3) (4). Despite its preference for coastal and wetland areas, the white-bellied sea eagle is also found in grassland, heathland, woodland, forested and, occasionally, urban areas (4).

The breeding habitat of the white-bellied sea eagle, which can be at the coast, further inland or on offshore islands, is generally tall, open forest close to water, although nests have sometimes been found in rainforest or in remnant trees on cleared land (4).

Despite generally being seen singly or in pairs (2) (4) (5), the white-bellied sea eagle is known to occasionally congregate in areas where there is abundant food available (4). While immature white-bellied sea eagles tend to disperse from the area in which they hatched, most adults of this species are sedentary, although they are capable of travelling long distances in search of food or in response to drought conditions (4).

This species feeds on a wide variety of aquatic species, including fish, sea snakes, water birds and marine turtles (4) (8) (10) (11) (16), but may also prey on land mammals (4) (8) (16), including domestic livestock (4).

Foraging flights generally occur over large expanses of open water, but may sometimes take place over open terrestrial habitats, including grasslands (4). The white-bellied sea eagle makes shallow glides over the surface of the water, performing spectacular swoops and dives to snatch its prey (2) (7) (10) (11), usually with one foot (4) and without entering the water (9) (11). This species also feeds on carrion (2) (8) (11), and is known to steal prey from other birds (2) (4) (9) (11). Interestingly, the white-bellied sea eagle has been recorded following dolphins, to catch flushed prey. If small, prey items are usually consumed in flight, but larger items are generally carried back to a feeding platform, or are occasionally eaten on the ground (4).

It is thought that the white-bellied sea eagle is capable of breeding at around 6 years of age, and may live for up to 30 years, although the mortality rates of young, newly independent birds is high (4). Following an acrobatic courtship display that includes somersaults and stoops (3), the white-bellied sea eagle forms a monogamous pair that mates for life and defends a breeding territory against other sea eagles (4). Should one of the pair die, it is soon replaced (4).

In southern Australia, the breeding season of the white-bellied sea eagle extends from June to January or February, while in northern Australia it tends to start one or two months earlier (4), lasting from May to October on Barrow Island off Australia’s northwest coast (8). The white-bellied sea eagle’s large nest, which can be two to three metres across and up to four metres deep (17), is built with sticks and lined with leaves, grass and seaweed (4) (8) (9) (10). The nest is often built in a tall tree near water (9) (11), although sometimes mangroves, cliffs, caves and rocky outcrops are used as nesting sites (4). The same nest may be used year after year (4) (8) (10).

White-bellied sea eagle eggs are white in colour and are laid in clutches consisting of between one and three eggs (4), with two being most common (4) (8) (10). The eggs are incubated for about six weeks, mostly by the female (4), although the male will sit on the eggs while the female feeds (8). White-bellied sea eagle chicks are fed by both adults, and do not leave the nest until 65 to 70 days after hatching. The adult birds continue to feed their young for up to three months after the fledglings have left the nest, but will then drive the young birds out of the breeding territory. In two-egg clutches, typically only one young is fledged, and if a clutch is unsuccessful, adult pairs will lay a second clutch (4).

Although it has a relatively small population size, the white-bellied sea eagle has an extremely large range (13), and is not considered to be globally threatened (4) (13). However, this species’ population trend appears to be decreasing (13), and although widespread in Australia, the white-bellied sea eagle is known to be declining locally in a number of states. This is thought to be the result of human disturbance of nesting pairs (4) (18), as the species is particularly sensitive to disturbance during the early stages of the breeding season and may abandon nests and young if exposed to human activity (4).

The loss of habitat due to land development is another main threat to the white-bellied sea eagle (4). Land clearance reduces the availability of suitable breeding habitat for the birds, thus greatly decreasing breeding success (4) (18). Poisoning and shooting are also potential threats to the white-bellied sea eagle, which may be targeted as it occasionally feeds on domestic livestock such as goats and chickens. The deterioration of inland water resources may also be contributing to the decline of the white-bellied sea eagle (4).

As well as in Australia, declines in the white-bellied sea eagle have been recorded in Thailand and elsewhere in Southeast Asia. Although there is no specific information available regarding the threats to this species in this part of its range, they are thought to be similar to those it faces in Australia (4).

The white-bellied sea eagle is protected in Australia as a result of its listing under the Environment Protection and Biodiversity Conservation Act 1999 (4) (8), and, like other species, it is protected on Barrow Island and its surrounds (8). This species also receives some protection under its listing on Appendix II of the Convention on International Trade in Endangered Species (CITES), which means that trade in the white-bellied sea eagle should be strictly monitored and controlled (4) (6). In addition, the white-bellied sea eagle is listed under the China-Australia Migratory Bird Agreement (CAMBA), which aims to minimise damage to key areas used by migratory birds which migrate between the two countries (4).

The white-bellied sea eagle also receives state-specific protection in certain parts of its range. It is classified as ‘Threatened’ in Victoria under the Flora and Fauna Guarantee Act 1988, and as ‘Vulnerable’ in Tasmania under the Threatened Species Protection Act 1995 (4).

Several management actions have been proposed to help conserve the white-bellied sea eagle, including protecting suitable habitat on public land, establishing buffer zones around nest sites to minimise human disturbance, conducting annual surveys of the species, and introducing a public awareness programme to help educate the public about this species, its status and its conservation (4).

Find out more about the white-bellied sea eagle and other birds of Barrow Island: